It is free, I use it all of the time and have never paid a cent. You can choose the free or paid version. Also you can Pin your own music onto your phone so it's physically there.I really want to use google music but I absolute hate it as a player. Also,it's not free . It's like $10 a month or something. Also I like not having to rely on data/WiFi availability to listen to music I own.
If I pinned my songs to my phone I'd just keep my songs on my phone and use Poweramp like I have been for 6 years. I had the turbo for a minute and burned through my data just looking at pictures.It is free, I use it all of the time and have never paid a cent. You can choose the free or paid version. Also you can Pin your own music onto your phone so it's physically there.